Hydrostatic pressure-actuatable nonretrievable packer



June 30, 1964 c. c. BROWN 3, 3 4 HYDROSTATIC PRESSURE-ACTUATABLE NON-RETRIEVABLE PACKER Filed June 27, 1962 2 Sheets-Sheet l wife a. Bean N c INVENTOR.

June 30, 1964 c. c. BROWN 3,139,140

HYDROSTATIC PRESSURE-ACTUATABLE NON-RETRIEVABLE PACKER Filed June 2'7, 1962 2 Sheets-Sheet 2 BY ,6 P

A TTOENE Y United States Patent 3,139,140 HYDROSTATIC PRESSURE-ACTUATABLE NON- RETRIEVABLE PACKER Cicero C. Brown, Brown Oil Tools, Inc., R0. Box 19236, Houston, Tex. Fiied June 27, 1962, Ser. No. 205,781 14 Claims. (Cl. 166-120) This invention relates to hydrostatic pressure-actuated well packers, and more particularly to non-retrievable or so-called permanent set packers which are actuated by hydrostatic pressures of well bore fluid.

Hydraulic pressure-actuated well packers which are presently in use require the provision of high pressure pumps and other auxiliary surface equipment for supplying and delivering actuating fluid under suitable pressures to such packers. Such surface equipment is expensive and frequently is not available on the well at the time packers are run and must be brought in from other places, thereby adding to the cost of setting such packers.

Other types of fluid pressure-actuated packers employ explosive charges for pressurizing a body of actuating fluid enclosed within the packer body. While packers of this type do not require the same kind of surface equipment as is required for other hydraulic pressure-actuated packers, they do, nevertheless, require some other type of surface equipment for setting off the explosive charges, and are subject to various operating difliculties.

The principal object of the present invention is to provide a hydraulic pressure-actuated packer which eliminates the need for pumps and other external pressurizing equipment for actuating the packer.

A principal object of this invention is the provision of a hydraulic pressure-actuatable packer which employs the hydrostatic head of the well bore fluid to actuate the packer.

An important object is the provision of a permanent set packer which is actuatable by the hydrostatic head of the well bore fluid and which may be run into the well either on a wire line or on a tubing string.

A further object is to provide a packer of the character described employing force-multiplying means for increasing the normal pressure exerted by the hydrostatic head of the well bore fluid on expansible elements of the well packer to set the packer.

An additional object of this invention is to provide a permanent set packer of the type described employing a differential area piston which is actuated by the hydrostatic head of fluid in the well bore to pressurize a body of pressurizing fluid enclosed in the packer body, in order to set the packer.

Still another object of this invention is the provision of a hydraulic pressure-actuated packer of the permanent set type having in combination therewith a setting tool actuatable by the hydrostatic head of fluid in the well bore to set a packer.

Other and more specific objects and advantages of this invention will become more readily apparent from the following detailed description when read in conjunction with the accompanying drawing which illustrates one useful embodiment in accordance with this invention.

In the drawings:

PEG. 1 is a longitudinal, quarter sectional view, showing the packer and setting tool assembly in running position in the well before the packer is set;

FIG. 2 is a view similar to FIG. 1, showing the packer in set position in the well;

FIG. 3 is a view similar to FIG. 2, but showing the setting tool released from the set packer; and

FIG. 4 is a view similar to FIG. 3 in which the packer is shown connected to a production string of tubing.

Referring to the drawings, there is shown a packer,

3,139,140 Patented June 30, 1964 designated generally by the letter P, of the so-called permanent-set type, which to those skilled in the art designates a form of packer which once set in a well bore is non-retrievable and will usually be removed by drilling it out when such removal becomes necessary. In such packers, the parts will normally be made of drillable or relatively frangible metals and composition materials.

Packer P is generally of the same form as that illus trated in my US. application Serial No. 544,659, filed November 5, 1955, now Patent No. 3,083,789, April 2, 1963, and comprises a tubular body 10 on the exterior of which is slidably mounted an annular seal element 11 buttressed at its opposite ends by upper and lower anchor assemblies, designated generally by the letters A and A respectively. Each of the anchor assemblies comprises an expander cone 12 about which is mounted a series of annularly arranged anchor slips 13, the expander cones tapering oppositely from the ends of the seal member. The slips of each assembly are pinned to their associated expander cone and to body 14 by means of shear pins 14 which normally hold the assemblies in retracted position on body 10. It will be understood that upon breakage of the shear pins, the assemblies and the seal member are slidable longitudinally of body 10.

The upper end of body 10 is threadedly received in the bore of a collar 15 which is positioned to engage slips 13 of upper assembly A; and forms a stationary abutment for this assembly. The lower end of body 10 is threadedly received in an annular head 16 having an annular recess 17 in the bore thereof defining a seat for .receiving a plug member 18 of a generally conventional form by means of which the bore 10a of body 10 may be closed at its lower end. Plug member 18 is of a form well-known in the art which may be withdrawn by exerting an upward pull on a portion thereof when it is desired to open the bore 100.

An annuar sleeve piston 19 is slidably disposed about the lower end of body 10 in engagement with slips 13 of the lower anchor assembly A and is provided with an internal packing 20 to form a slidable seal about body 16. Piston 19 is secured to a tubular skirt or sleeve 21 which extends'slidably overthe exterior of head 16 and is secured thereto by means of a shear screw 22. The length of skirt 21 is such as to provide a pressure chamber 23 between the upper end of head 16 and piston 19. Ports 24 extend through the wall of body 10 above the upper end of head 16 to provide communication between bore 10a of the body and pressure chamber 23. Piston 19 pro vides a movable abutment engageable with the lower end of anchor assembly A through which axial compression may be exerted on the anchor assemblies and the intervening seal member for actuating the packer and anchor elements, as will appear subsequently. With plug 18 in place, bore 19a forms a chamber which is filled with a suitable hydraulic fluid F, which may be water, oil, or any other incompressible liquid.

When pressure is applied to fluid F, this pressure will be transmitted thereby through ports 24 into chamber 23 and acting against piston 19 will break shear screws 22 and force piston 19 upwardly against the slips of the lower anchor assembly. As the pressure on piston 19 increases, shear pins 14 will be broken and the upward movement of the anchor assemblies, being opposed by the fixed abutment provided by collar 15, will actuate the anchor-and-seal elements and set the packer by expanding seal element 11 into sealing engagement with the wall of easing C and forcing anchor slips 13 over expander cones 14 radially into gripping engagement with the casing wall. Conventionally the anchor slips of the respec tive anchor assemblies will have oppositely facing buttress teeth to secure the packer to the well wall against movement in either direction once the packer is set.

.To actuate the packer, a setting tool designated generally by the letter T is employed. The setting tool comprises a tubular setting sleeve 30, the lower end of which extends about collar and is releasably secured thereto by means of shear screws 31. The upper end of sleeve is threadedly secured about a reducing bushing 32 which extends into the bore of sleeve 30 and has a bore 33 of lesser diameter than the bore of sleeve 36). At a point adjacent the upper end of collar 15, sleeve 30 is provided with an internal annular shoulder 34 having an axial .bore 35 somewhat smaller in diameter than bore 10a of the packer body. A differential area piston, designated generally by the numeral 36, is slidably mounted in the bore of sleeve 30 and comprises a lower relatively smaller diameter cylindrical section 37 and an upper relatively larger diameter cylindrical section 38. Section 37 is dimensioned to extend slidably through bore 35 of shoulder 34 into the upper end of bore 10a of the packer body into contact with the body of fluid F. Larger diameter section 38 is dimensioned to slidably engage the inner wall of sleeve 30 above shoulder 34. Seal packing 39 is provided in the wall of bore 35 to form a slidable fluidtight seal with piston section 37, and piston section 38 is provided with seal packing 40 in its external periphery to form a slidable fluid-tight seal with the inner wall of sleeve 30.

The portion of the bore of sleeve 30 which is confined between the seals 39 and 40 comprises a chamber 41 which will contain air at substantially atmospheric pressure and this air trapped between the seals serves as a pneumatic cushion which is compressible and expandible in response to the movements of piston 36.

It' will be seen that differential area piston 36 acts as a pressure-multiplying or pressure-increasing means by which the pressure. transmitted by piston section 37 to fluid P will be greater than that acting on the pressure actuatable area of piston section 38 by a factor corresponding to the ratio of the pressure actuatable area of piston section 38 to the pressure actuatable area of piston section 37. Thus, if this area ratio is 4:1, for example, a given pressure exerted on upper piston section 38 will be increased substantially four-fold by lower piston section 37 and transmitted to fluid P which will be trapped between seal 39 and plug member 18. t

A tubular mandrel 42 is threadedly inserted into the upper end of the bore of bushing 32 and its upper end is adapted to be connected to an operatin string S, which may be a wire line string or a tubing string. Mandrel 42 is provided with ports 43 extending through the wall thereof; Ports 43 are controlled by means of a sleeve valve 44 slidably disposed about the exterior of mandrel 42 and provided with upper and lower seal packings 45- -45, which are adapted to seal off ports 43 from com munication with the bore of easing C when the sleeve valve is in the upperposition illustrated vin FIG. 1. A collar 46, forming the connection between the upper end of mandrel 42 and the operating string S serves to limit upward movement of sleeve valve 44 to a position closing ports 43. Valve 44 is provided with a plurality of radially extending drag springs 47 which frictionally engage the wall of casing C. Ports 43 can be opened to communicate with thebore of casing C by upward movement of the mandrel relative to valve 44, as seen in FIG. 2.

Operation of the device is as follows: The packer and setting tool will be assembled on the operating string, as

shown in FIG. 1, the packer and anchor elements being in their retracted positions. Plug member 18 will be seated in the bore of head 16 and bore 10a will be filled with fluid F to a level to be in contact with the lower end of piston section 37. As the string is run into the well, the friction of springs 47 against the wall of casing C will hold sleeve valve 44 in its uppermost position abutting collar 46 and closing-off ports 43 from communication with the bore of casing C.

When the string has been lowered in the casing to the point at which the packer is to be set, the operating string will be raised and the friction of drag springs 47 on the wall will hold the valve stationary as mandrel 42 moves upwardly relative thereto to a point at which ports 43 will be above packings 45, thereby opening ports 43 and placing the bore of mandrel42 in communication with the head of fluid in the bore of easing C. The latter, in the usual case, will be filled with fluid, which may be drilling mud, formation fluids, or any other type of liquid which is commonly present in a well bore. If necessary water or other liquid may be introduced into casing C to provide a liquid column having the desired hydrostatic head. Opening of ports 43 will allow this fluid, under its hydrostatic head which may be represented by a column of several thousand feet in height, to flow through ports 43 into the bore of mandrel 42 and thence into the bore of sleeve 30 above enlarged section 38 of the differential area piston. The hydrostatic pressure thus exerted against the relatively larger area of section 38 of the piston will cause the pressure in the confined fluid F to be increased over that exerted by the hydrostatic head outside the packer by an amount determined by the ratio of the area of enlarged section 38 to that of section 37. This increased pressure will be applied by piston section 37 to fluid F and transmitted by the latter through ports 24 into chamber 23 and thence against piston 19. The magnitude of this force will be suflicient to break shear screws 22, permitting piston 19 to be forced upwardly by the fluid pressure and to transmit this force through the lower slip assembly A to seal member 11 and thence to upper anchor assembly A The longitudinal force thus exerted on the anchor assemblies will act to break shear pins 14 in each anchor assembly, allowing the relative movement between the slips and cones required to move the slips radially into anchoring engagement with the wall of casing C, while at the same time compressing and expanding seal element 11, and

thereby setting the packer, as seen in FIG. 2.

Hydrostatic pressures of from about 300 or 400 pounds per square inch to about 1000 pounds per square inch usually will be adequate to provide setting pressures sufiicient to effectively set and anchor the packer. These hydrostatic pressures will be provided easily by hydrostatic heads offrom 1000 to 2000 feet of salt water or similar fluid in the well bore and will result in considerably increased effective setting pressures, depending upon the area ratio of piston section 38 to piston section 37. Once set, the packer will be fixed against longitudinal movement in either direction by the gripping action of the opposed slips on casing C.

As the applied pressure will be in excess of that required .to set the packer, release of the setting tool will occur more or less automatically. The pressure of fluid P will be exerted against the area defined by shoulder 34 and by designing shear screws 31 to break ata pressure somewhat greater than the setting pressure, these screws will be sheared as soon as the applied pressure reaches the required magnitude. The breaking force on the shear screws may be supplemented, if necessary, by an upward pull or other suitable directed force directed against the shear screws throughthe operating string. The anchor assemblies will be sufficiently strongly set to the wall of easing C to permit the necessary force to be exerted to break the shear screws, as illustrated in FIG. 3.

When the setting tool has been withdrawn, plug member 18 may be withdrawn by means of a conventional fishing tool to open the bore of the packer and then a production pipe string 0, carrying a conventional seal nipple 50 fitted with seal packing 51, may be run into the well and inserted into'the bore of body 10 to seal therewith and open the Well to production through the bore of the packer and production string 0. Seal nipple 50'is provided with an external shoulder 52, which is adapted to engage the upper end of collar 15 to limit inward movement of the seal nipple into body 10 of the packer, as illustrated in FIG.'4.

While the illustrative embodiment shows a sleeve-type valve operable by relative longitudinal movement of the operating string for controlling ports 43, it will be understood that any other conventional type of valve, or any suitable valve means other than a sleeve valve, may be employed for controlling communication between the interior of the setting sleeve and the Well bore. Numerous valves are well-known to those skilled in the oil well art which may be operated either in the manner shown in the illustrative embodiment, or by rotating the operating string, and it will be understood that this invention is not to be limited to the use of any particular form of valve suitable for controlling fluid communication between the interior and exterior of the setting sleeve.

It will be understood that various changes and modifications may be made in the details of the illustrative embodiment within the scope of the appended claims, but without departing from the spirit of this invention.

What I claim and desire to secure by Letters Patent is:

1. A hydrostatic pressure-actuated packer for use in a Well bore containing a column of liquid, comprising, a tubular packer body having a bore containing a body of a hydraulic pressure fluid confined therein, an annular anchor-and-seal assembly slidably mounted on the exterior of the packer body, a fixed abutment member and a longitudinally movable abutment member mounted on the packer body above and below said assembly, said movable abutment member being operable in response to the pressure of said pressure fluid to radially expand said anchor-and-seal assembly into gripping and sealing engagement with the wall of the well bore, port means through the wall of said tubular body operably communicating said pressure fluid to said movable abutment member, pressure-multiplying means mounted on the packer body in pressure-transmitting relation to said pressure fluid, and valve means carried by the packer body operable to direct the head of said liquid in the well bore exteriorly of said packer body against said pressuremultiplying means.

2. A hydrostatic pressure-actuated packer according to claim 1, wherein said pressure-multiplying means is a differential area piston.

3. A hydrostatic pressure-actuated packer according to claim 1, wherein said movable abutment member comprises a sleeve piston having the bore thereof in communication with said port means.

4. A hydrostatic pressure-actuated packer according to claim 1, having frangible means initially securing said anchor-and-seal assembly in retracted position on the packer body, said frangible means being breakable upon the application of said pressure fluid to said movable abutment member.

5. A hydrostatic pressure-actuated packer for use in a well bore containing a column of liquid, comprising, a tubular packer body having a bore containing a body of a hydraulic pressure fluid confined therein, an annular anchor-and-seal assembly slidably mounted on the exterior of the packer body, a fixed abutment member and a longitudinally movable abutment member mounted on the packer body above and below said assembly, said movable abutment member being operable in response to the pressure of said pressure fluid to radially expand said anchor-and-seal assembly into gripping and sealing engagement with the wall of the well bore, port means through the wall of said tubular body operably communicating said pressure fluid to said movable abutment member, packer-setting means comprising a sleeve member coaxial with and releasably secured to the upper end of said packer body, pressure multiplying means mounted in said sleeve member in pressure-transmitting relation to said pressure fluid, and valve means carried by the sleeve member operable to open and close communication between the well bore and the interior of said sleeve member above said pressure-multiplying means.

6. A hydrostatic pressure-actuated packer according to claim 5, wherein said pressure-multiplying means is a differential area piston having its larger area positioned for exposure to the head of said column of liquid and its smaller area in pressure-transmitting relation to said body of hydraulic pressure fluid.

7. A hydrostatic pressure-actuated packer according to claim 5, wherein said valve means comprises a tubular mandrel having ports through the Wall thereof and a closure member slidably mounted on the mandrel and operable by relative movement of the mandrel to open and close said ports.

8. A hydrostatic pressure-actuated packer according to claim 5, wherein said movable abutment member comprises a sleeve piston having the bore thereof in communication with said port means.

9. A hydrostatic pressure-actuated packer for use in a well bore containing a column of liquid, comprising, a tubular packer body having a bore, a removable plug member closing the lower end of said packer body to define a chamber therein, a body of a hydraulic pressure fluid confined in said chamber, an annular anchor-andseal assembly slidably mounted on the exterior of the packer body, a fixed abutment member and a longitudinally movable abutment member mounted on the packer body above and below said assembly, said movable abutment member being operable in response to the pressure of said pressure fluid to radially expand said anchor-andseal assembly into gripping and sealing engagement with the Wall of the well bore, port means through the wall of said tubular body communicating said pressure fluid from said chamber to said movable abutment member, packer-setting means comprising a tubular housing releasably secured to said packer body, pressure-multiplying means mounted in said housing in pressure-transmitting relation to said pressure fluid, and valve means mounted on said housing operable to open and close communication between the well bore and said housing to control application of said liquid to said pressure-multiplying means.

10. A hydrostatic pressure-actuated packer according to claim 9, wherein said pressure-multiplying means is a differential area piston having its larger area positioned for exposure to the head of said column of liquid and its smaller area in pressure-transmitting relation to said body of hydraulic pressure fluid.

11. A hydrostatic pressure-actuated packer according to claim 9, wherein said valve means comprises a tubular mandrel connected to said housing, ports through the wall of said mandrel, and a closure member mounted about the mandrel and operable by relative movement therebetween to open and close said ports.

12. A hydrostatic pressure-actuated packer for use in a well bore containing a column of liquid, comprising, a tubular packer body having a bore, a removable plug member closing the lower end of said packer body to define a chamber therein, a body of a hydraulic pressure fluid confined in said chamber, an annular anchor-andseal assembly slidably mounted on the exterior of the packer body, a fixed abutment member and a longitudinally movable abutment member mounted on the packer body above and below said assembly, said movable abutment member being operable in response to the pressure of said pressure fluid to radially expand said anchor-andseal assembly into gripping and sealing engagement with the wall of the well bore, port means through the wall of said tubular body communicating said pressure fluid from said chamber to said movable abutment member, packer-setting means comprising a tubular housing releasably secured to said packer body, said housing having relative larger and smaller diameter bore portions, a differential area piston longitudinally slidable in said housing having larger and smaller area sections respectively slidable in said relatively larger and smaller diameter bore portions, said smaller area section of said piston being in pressure-transmitting relation to said pressure fluid, and valve means mounted on said housing operable to open and close communication between the well bore and the interior of said housing above said larger area piston section to control application of the head of said column of liquid to said difierential area piston. v

13. A hydrostatic pressure-actuated packer for use in a Well bore containing a column of liquid, comprising, in combination With a hydraulic pressure-actuatable well packer, a body of a hydraulic actuating fluid confined Within the packer and operable in response to application of pressure thereto to actuate the packer, pressure-multiplying means carried by the packer operably disposed in pressure-transmitting relation to said body of hydraulic actuating fluid, and valve means carried by the packer operable to control communicationrof the pressure of the column of liquid in the Well bore to the pressuremultiplying means.

14. A hydrostatic pressure-actuated packer according to claim 13, wherein said pressure-multiplying means comprises a differential area piston having a larger area portion exposed tosaid column of liquid in the Well bore and a smaller area portion in pressure-transmitting relation to said body of hydraulic actuating fluid.

References Cited in the file of this patent UNITED STATES PATENTS 

1. A HYDROSTATIC PRESSURE-ACTUATED PACKER FOR USE IN A WELL BORE CONTAINING A COLUMN OF LIQUID, COMPRISING, A TUBULAR PACKER BODY HAVING A BORE CONTAINING A BODY OF A HYDRAULIC PRESSURE FLUID CONFINED THEREIN, AN ANNULAR ANCHOR-AND-SEAL ASSEMBLY SLIDABLY MOUNTED ON THE EXTERIOR OF THE PACKER BODY, A FIXED ABUTMENT MEMBER AND A LONGITUDINALLY MOVABLE ABUTMENT MEMBER MOUNTED ON THE PACKER BODY ABOVE AND BELOW SAID ASSEMBLY, SAID MOVABLE ABUTMENT MEMBER BEING OPERABLE IN RESPONSE TO THE PRESSURE OF SAID PRESSURE FLUID TO RADIALLY EXPAND SAID ANCHOR-AND-SEAL ASSEMBLY INTO GRIPPING AND SEALING ENGAGEMENT WITH THE WALL OF THE WELL BORE, PORT MEANS THROUGH THE WALL OF SAID TUBULAR BODY OPERABLY COMMUNICATING SAID PRESSURE FLUID TO SAID MOVABLE ABUTMENT MEMBER, PRESSURE-MULTIPLYING MEANS MOUNTED ON THE PACKER BODY IN PRESSURE-TRANSMITTING RELATION TO SAID PRESSURE FLUID, AND VALVE MEANS CARRIED BY THE PACKER BODY OPERABLE TO DIRECT THE HEAD OF SAID LIQUID IN THE WELL BORE EXTERIORLY OF SAID PACKER BODY AGAINST SAID PRESSUREMULTIPLYING MEANS. 